The present invention relates to improvements in the technology relating to inexpensive and reliable lighting sources and more particularly to a human powered flashlight free of batteries and free of external integrity breaches and which is engineered to use light efficiently.
Production of light with a portable light source or flashlight is a well known expedient in which a tubular body is fitted with a number of series connected batteries. The disadvantages of conventional flashlights with this conventional configuration are generally (1) breach of internal external integrity from having to access the battery compartment fairly regularly to replace batteries, and (2) other breaches of external integrity associated with light bulb changes at the front of the device and from a mechanical linkage relating to the on and off switch.
In some devices especially built for underwater use, a series of multiple xe2x80x9coxe2x80x9d rings may be employed for water sealing.
However, when these structures are employed at points likely to be repeatedly accessed, such as the rear entrance to the battery compartment, degradation will likely occur resulting in an eventual breach of sealing integrity.
Other step have been taken to insure integrity such as placing a flexible push button cover over the on and off switch, but these covers tend to either leak early in their functional life at the ring of circular attachment, or later in their functional life by cracking or punching breach. Seals around the bulb changing entrance, typically the front lens cover have proven to be more secure.
Production of energy for lighting using generator devices are also known. In some cases a crank generator is provided with the crank extending through the housing, creating another source of housing fluid breach. Either a scientifically closely toleranced bearing must be provided to keep moisture out (close tolerance along with friction loss) or the generator must itself be water proof. The generator is itself a complex mechanical machine and also prone to water damage, rust, and excessive wear.
Because of the breakdowns cited above, non-battery flashlights are generally unreliable as an emergency or long storage time period source of lighting, and particularly in a harsh or moist environment.
Further, the majority of personal lighting products are generally inefficient as being operated using an incandescent (heated filament) light source which is not conserving of energy usage per unit of illumination. Most generator models require considerable hand crank input to effect any significant light output over time.
What is therefore needed is a more compact, more isolated source of emergency lighting which is human powered, but which is also efficient in operation. The device should be impact resistant and have relatively few moving parts and no intense, high force, small area wear surfaces.
The light generating device of the present invention utilizes a large centrally located magnet which is mounted to slide past a magnet pickup or current induction wire which may be preferably mounted at a center point of travel in a tubular housing having a tubular chamber through which the magnet travels. A pair of elastomeric bumpers are located each at the end of the tubular chamber. Each of the elastomeric bumpers are supported by its own spring secured against the sides, end or both of the terminal ends of the tubular chamber. The mounting sequence is first chamber end or structure to first spring, to first bumper to freely slidable or translatable magnet to second bumper secured by second end or structure of the chamber. The result is a device which both facilitates the manual movement of the flashlight body so that the magnet slides past the center magnet pickup or current induction wire, and also conserves the residual momentum of the magnet once it has traveled past the magnet pickup or current induction wire by providing a bumper and spring to conserve some of the mechanical energy going in the other direction.
Where the size of the magnet is matched to the length of the tubular chamber and the size of the springs, a matched, sealed mechanical system is formed which can be continuously operated with minimal wrist energy. The mechanical input energy is intended to be stored regardless of whether the light is operational during charging or not. The energy consumption of the lamp should be such that the mechanical charging action can keep sufficient energy stored in advance of its consumption in light production so that the flashlight of the invention can be continued to be utilized even when any temporary store of energy provided is depleted. This action is contemplated to be performed by shaking the flashlight several times to input mechanical and then electrical energy into storage, followed by a period of illumination from an energy reservoir, which may be chemical or capacitor or other.
In addition, an activation switch for external control is had with an external smaller magnet which operates in conjunction with a reed switch to enable mechanical activation without the necessity to form a mechanical linkage between the inside and outside of the flashlight.